US2329471A - Electrical terminal - Google Patents

Description

Sept. 14, 1943. D. H. KING ELECTRICAL TERMINAL Filed Aug. 7, 1942 2 Shaets-Sheet 1 FIG. 7

A T TORNE V Sept. 14, 1943., D. H. KING 2,329,471

ELECTRICAL TERMINAL Filed Au 7. 1942 2 Sheets-Sheet 2 F7619 F [6. l0

INVENTOR 0. H. KING A TTORNEV Patented Sept. 14, 1943 UNITED STATES PATENT OFFICE ELECTRICAL TERMINAL Douglas H. King, Short Hills, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application August '1, 1942, Serial No. 453,953

7 Claims.

This invention relates to electrical terminals and more particularly to electrical terminals con structed and arranged for mounting in a support by having a portion of the terminal driven into a recess provided in the support.

The object of the invention is to provide a terminal which when driven into a recess formed in a support of insulating material will remain securely anchored in the support.

A feature of the invention resides in the form and construction of one end portion 01' the terminal.

In the drawings:

Fig. 1 is a view in perspective of one form of the terminal embodying the invention;

Fig. 2 is a view, partly in section, of a fragmentary portion of an insulating support with a' recess formed therein and the lower portion 01' the terminal, Fig. 1, placed in the recess;

I Fig. 3 corresponds to'Fig. 2 but shows the terminal driven within the recess so that the terminal is securely anchored in place Fig. 4 is a view in perspective of an insulating support with two terminals of this invention secured in place and with one of the terminalsv showing a modification of the invention and" indicating that the terminal may be of either straight or bent iorm;

Fig. 6 shows the lower portion 01 the terminal, Piglet 5, placed in the recess in an insulating sup- P Fig. 7 corresponds to Fig. 6 but shows the terminal secured in place;

Fig. 8 shows a modified form of the terminal;

Fig. 9 shows the lower end of the terminal, Fig. 8, placed in a recess in a support; and

Fig. 10 corresponds to Fig. 9 but shows the terminal secured in place.

Terminal blocks and other insulating supports for terminals are often made of thermoplastic insulating material such, for instance, as hard rubber. The terminal to be supported in the insulating support is often set and held in place in a. mold while insulating material is being molded to form the required support. In doing position during-the molding operation.

In some cases inorder to eliminate the necessity of.using jigs or fixtures to hold the terminals in position during the molding oi the insulating support, recesses have been formed in the insulating support either during or after the. molding operation, the recesses being provided to receive the terminals. After the insulating support-is molded and a recess isformedtherein the terminal is driven into the recess and is held in place by frictional engagement of the terminal against the walls defining the recess. make it more diiiicult to withdraw the terminal from the recess teeth have been provided on the portion of the terminal entered in the recess, the idea being that the teeth will dig into the walls of the recess. In such arrangements, however, the recess is made smaller than the entered portion of the terminal and when the terminal isbeing driven into place the teeth cut their way into the Walls of the recess and form grooves behind them through which the teeth may pass when separation of the terminal from the insulating support is attempted.

My invention is an improvement in driven-in type terminal structures and arrangements and provides a construction and arrangement which permits ready placing of the terminal in the recess and when the terminal is driven down within the recess the entered portion of the terminal takes such form that the terminal remains securely anchored in place.

In Fig. 1 the terminal I which may be made of sheet metal or other suitable material, is provided with leg members 2 and 3 extending in substantial parallel spaced relation on opposite sides of an aperture 4 formed longitudinally in the lower portion of the terminal. The aperture 4 resembles an inverted keyhole but is not entirely closed at the lower end when the terminal i is originally formed. The lower end of the leg member 2 is provided with a foot 5 which is toed inwardly toward a corresponding foot 6 formed on and extending from the leg member 3. The feet 5 and 6 slope downwardly and inwardly toward each other and are in almost toe-to-toe engagement in Fig. 1. The upp r end of the foot 5 is narrowed at l and the upper end of the foot 5 is narrowed at 8 to make the feet more readily bendable at these points. The lower ends of the feet 5 and 6 are rounded at 9 and i0, respectively, and the outer edges of the feet5 and 6 are curved at H and I2 for a purpose to be later explained. The leg members 2 and 3 are reduced in width at the respective-points l3 and M to make the leg membersmore readily bendable at these In an eflort to points and the outer edges of the leg members 2 and 3 are contoured to provide teeth I5 and I5, the teeth I5 and I5 on each leg member being directed in the direction of the line of thrust of the leg member. The advantage provided by this arrangement of the teeth will be subsequently explained. A tapped hole II is provided in the upper portion of the terminal I to receive a screw, not shown, but which may be employed in fastening a wire to the terminal.

As shown in Fig. 2 a tapered recess I5 is formed in a support I5 made of insulating material, the recess I5 being rectangular in form, the rectangular form being longer at the top than at the bottom. The depth of the recess I8 is slightly less than the length of the aperture 4 and the lower end 25 of the recess is flat. The end walls 2| and 22 of the recess I5 slope inwardly from the top to the bottom. The length of the recess I5 gradually decreases from the top to the bottom and is so dimensioned that when the terminal I is being placed in the recess the teeth I5 and I5 on the leg members 2 and 3 will not cut into the end walls 2| and 22 until the teeth 1 5 and I5 on the leg members are part way down the recess I5. Since the feet 5 and 5 are not in mutual. engagement when the terminal I is originally formed the leg members 2 and 3 may be slightly sprung toward each other as the terminal I is being moved to the position shown in Fig. 2, the springing of the leg members 2 and 3 toward each other being accomplished by the camming action of the end walls 2| and 22 against the teeth I5 and I5.

When the terminal I reaches the position shown in Fig. 2 the feet 5 and 5 are in toe-to-toe engagement and are in engagement with the lower wall 20 of the recess I5. After the terminal I is placed in the recess I8 in the position shown in Fig. 2 the terminal is driven downwardly in the recess I8 to the position shown in Fig. 3. During this driving-in operation the feet 5 and 5 bend at the narrowed portions I and 8 and since the feet 5 and 6 are in toe-to-toe engagement the leg members 2 and 3 cannot come closer together. The feet 5 and 5 are moved into substantially fiatfoot engagement with the lower wall 20 of recess I8 and into the position shown in Fig. 3. In taking this position the feet 5 and 5 force the leg members 2 and 3 away from each other so that the teeth I5 and I5 are driven into the end walls 2| and 22 of the recess I5, the leg members 2 and 3 bending at the narrowed portions I3 and I4 and so that the aperture 4 shown in Figs. 1 and 2 takes the form of the aperture 23 shown in Fig. 3. The feet 5 and 5 are curved at H and I2, respectively, so that the feet 5 and 6 will rock on the fiat surface of the lower wall 2|) of the recess I5 when the terminal I is being driven to final position. The roundedends 9 and I0 permit slight turning up of the toe-to-toe engaged portions of feet 5 and 5 and so that the feet 5 and 5 when moving to final position pass through a dead center position relative to each other and in final position are slightly above the dead center position.

The teeth I5 and I5 on each leg member as above mentioned are formed and arranged so that they point in the direction of the line of thrust of the leg member. The advantage in this construction and arrangement of the teeth I5 and I5 is that when the terminal I is being driven down in the recess I5 and so that the tooth I5 on leg member 2, for instance, cuts a way for itself in the wall 2| of the recess I8, the tooth I5 in cutting a way for itself in the wall 2| will force material from the wall 2| into the valley portion 24 between the teeth I5 and I5 and against the upper wall 25 of the tooth I5. forced down by the tooth I5 against the upper wall 25 of the tooth I5 and into the valley portion 24 serves in some measure to prevent withdrawal of the leg member 2 from the recess I5. It will be seen that in orderto withdraw the leg members 2 and 3 from the reces I5 it would be necessary to move the leg members 2 and 3 toward each other and that this is prevented by the feet 5 and 5 which are in toe-to-toe engagement and which would have to be moved downward through and beyond dead center position before the leg members 2 and 3 could come closer together.

Fig. 4 shows a terminal block 25 equippedwvith terminals made in accordance with this invention, the terminals 21 and 28 having been driven down within the tapered recess I5 formed in the terminal block 25. The terminal 2! may be like the terminal I shown in Figs. 1, 2 and 3 and be equipped with a screw 29 in the tapped hole II. The terminal 25 may be of like construction but having the outer end portion3|| bent angularly relative to the end portion secured in the block 25.

In the modification shown in Figs. 5, 6 and 7 the terminal 3| follows, in general, the pattern of the terminal I above described and is provided with leg members 32 and 33 extending in substantially parallel spaced relation on opposite sides of an elongated aperture 34 formed longitudinally in the lower portion of the terminal. The lower end of the leg member 32 is provided with a foot 35 which is toed inwardly toward a corresponding foot 35 formed on andextending from the leg member 33. The feet 35 and 35 slope downwardly and inwardly toward each other and are in almost toe-to-toe engagement in Fig. 5. The leg member 32 is narrowed at 31, and the leg member 33 is narrowed at 35 to make the leg members more readily bendable at these points. The lower ends of the feet 35 and 35 are rounded at 39 and 45, respectively, and the outer edges of the feet 35 and 35 are curved at 4| and 42. The leg members 32 and 33 are reduced in width at the respective points 43 and 44 to make the leg members more readily bendable at these points, and the outer edges of the leg members 32 and 33 are contoured to provide teeth 45 and 45, the teeth 45 and 45 on each leg member being directed toward the top of the terminal. The terminal 3| may be straight as indicated by the dot-dash lines in the figure or may be bent as shown in full line and is provided with a tapped hole 41 to receive a screw, not shown, but which may be used in connecting a wire to the terminal.

In Fig. 6 the terminal 3| is placed in the tapered recess I5 formed in a support I9 made of insulating material, the recess I8 being of the form described in connection with Figs. 2 and 3 and having its depth slightly less than the length of the aperture 34. After the terminal 3| is placed in the recess I5, as shown in Fig. 6, and with the feet 35 and 35 in engagement with the lower wall 2|] in the recess I8 and with each other, the terminal 3| is driven downwardly in the recess I8 to the position shown in Fig. 7. If the terminal 3| is of bent form such as shown in full lines in Fig. 5, 2. lug 45 may be formed on the terminal 3| to serve as an anvil to receive a blow applied to the terminal in driving the terminal downwardly in the recess l5. During the driv- The material a terminal 5| is drivendownwardly m the recess a lng-in operation the leg members 32 and 33 bend to the position shown in Fig. 10. During this at the narrowed portions 31 and 33; respectively, and the feet 35 and 36 are in toe-to-toe engageement and move into substantiallyflat foot engagement with 'the lower wall 23 of the recess i3 and into the position shown in Fig. '7. In taking this position the feet 35 and 36 force the leg members 32 and 33 away from each other and so that the teeth 45 and are driven into the end walls 2| and 22 of the recess i3. the leg members 32 and 33 bending slightly outwardly from the narrowed portions 43' and .44 and so that the aperture 33 shown in Figs. 5 and 6 takes the form of the aperture 49, shownin Fig. 7. I g

,It will be seen in Fig. 7 that the teeth 45 and 46 driving-in operation the feet 55 and 56 bend at narrowed portions 51 and 58 and since the feet 55 and 56 are in toe-to-toe engagement the leg members 52 and-53 cannt,come closer together.

' The feet 55 and 56 are moved into substantially flat-foot position relative to the lower wall 23 of the recess i8'and'into the position shown in Fig. 10. In taking this'position the feet 55 and 56 force the leg members 52 and 53 away from each other and so that'the-corners 66 are driven into the end walls 2| and 22 of the recess It, the leg have been driven into the walls 2| and 22' of the I recess" and that each tooth 45 inmoving to its final position in the recess "has forced some of the material in the end wall of the recess against the upper portion 50 of the tooth 36. Also, that the feet 35 and 36 .in taking theirv final position have passedslightly above a dead center condition, and the leg members 32 and 33 by reason of the position of the feet 35 and 36 cannot easily be made to move towardeach'other if an effortis made to withdraw the terminal 3| from'the recess |8. l

In Fig. 8 which shows a modified form of the terminal there are no teeth on the leg members of the terminal. The terminal shown in this figure follows in other respects the general pattern of the terminal I shown in Fig. 1. The terminal 5| is provided with leg members 52 and 53 members" 52 and 53 bending at the narrowed portions 63 and '64 duringthis'outward movement of the leg members.

It win be seen as shown in Fig.1 that the corners 66 shown in Figs. 8 and 9 have become obtuse angles 68 thrust rather deeply into the walls 2| and 22 of the recess i6 and that the greaterqpor tion of the straight; outer edge 65 of each leg extending in substantially parallel spaced rela I tion on opposite sides of an aperture 54 formed longitudinally in the lower portion of the terminal. The lower end ofthe leg member 52 is provided with a foot 55 which is toed inwardly toward a corresponding foot 56 formedon and extending from the leg member 53. The feet 55 and 56 slope downwardly and inwardly toward each other and are in almost toe-to-toe engagement in Fig. 8. The upper end of the foot 55 is narrowed at 51 and the upper end of the foot 56 is narrowed at 58 to make the feet more readily bendable at these points. The lower ends of the feet 55 and 56 are rounded at 59 and 65, respectively, and the outer edges of the feet 55 and 56 are curved at Bi and 62 to permit the feet to rock on the lower end 20 of the recess l8 shown in Figs. 9 and 10. The leg members 52 and 53 are reduced in width at the respective points 63 and 64 to make the leg members more readily bendable at these points. The outer edges of the leg members 52 and 53 as above pointed out are not provided with teeth but are straight, each leg memher having a straight outer edge portion 65 extending to a corner 66 where the leg members 52 and 53 terminate in the feet 55 and 56, respectively. A tapped hole 61 is provided in the upper portion of the terminal 5| to receive a screw, not shown but which may be employed in fastening a wire to the terminal.

As shown on Fig. 9, the terminal 5| is placed in atapered recess l8 formed in the support |9 member extends into the wall of the tapered recess i8. Also that the taper of the lower portion of the terminal 5| in its final form is substantially opposite to the form of the recess Hi. It would be extremely difficult to remove the termin al 5| from the support i9, when the terminal 5| is in the final position shown in Fig. '10, since the leg members 52 and 53 are 'engaged in the walls 2| and 22 of the recess I8 and the legmembers52 and 53 are held in this final position by th toeto-toe engaged feet 55 and 56 which have-also passed upwardly beyond dead center position.

What is claimed is:

1. An electrical terminal suitable for mounting its leg member by an integral readily bendable portion, the feet on said leg members being arranged to engage each other in a toe-to-toe manner and cooperatively spread said leg members apart when the terminal is driven into the recess, and the feet on said leg members being operable during the drivin in of said terminal to move through and slightly above a dead center condition and so that they will be cooperatin to hold said leg members in spread apart condition in the recess in said'support and in holding engagement with walls of the recess.

2. An electrical terminal driven into a recess formed in a support of insulating material, said terminal comprising a pair of leg members ex-- tending in said recess, inwardly toed feet on said leg members engaging the bottom of said.

recess and engaging each other in a toe-to-toe manner, each of said feet being connected to its supporting leg member by a weakened portion which is bent during the driving in of said terminal. and said feet having been moved upwardly and slightly beyond a dead center condition but still cooperating to hold said leg members spaced apart in said recess and'in holding engagement with the walls of said recess.

3. An electrical terminal suitable for driving into a recess formed in a support of insulating material, said terminal comprising a pair of leg members arranged to enter said recess, a foot on each leg member toed downwardly and inwardly toward a corresponding foot on the'other leg member, the juncture of each foot and leg member being relatively narrow to make the structure readily bendable at these points, said feet being arranged to engage the bottom of said recess and to engage each other in a toeto-toe manner when said terminal is-inserted in said recess and said feet being arranged to operate in the manner of levers on said leg members and cooperate to force the lower ends of said leg members away from each other and so that said leg members will be forced into holding engagement with the walls of said recess and will be maintained in holding engagement with walls of said recess when said terminal is driven into said recess.

4. An electrical terminal suitable for driving into a recess formed in a support of insulating material, said terminal comprising a lower portion formed to provide spaced leg members teeth formed on the outer edges of said leg members, said teeth being directed in the line of thrust of said leg members, feet on said leg members extending angularly downward of said leg members and inwardly toward each other, said feet being arranged to engage each other in a toeto-toe manner and force said leg members outwardly within the recess and force said teeth into walls of the recess when said terminal is driven into the recess, said feet cooperating to hold said leg members in such' condition that said teeth are maintained in holding engagement with the walls of the recess.

5. An electrical terminal suitable for mounting in a support by driving a portion of the terminal into a recess formed in thesupp rt, said terminal comprising a lower portion having an elongated aperture formed therein, a pair of leg members extending in spaced relation and defining said aperture, a foot on each leg member sloping downwardly and inwardly toward a corresponding foot on the other leg member, teeth formed on the outer edge of each leg member, said teeth being directed toward the lower end of said terminal, said feet being readily bendable at the junctures of said feet with said leg members and being arranged to engage each other in toeto-toe manner and to outwardly thrust said leg members to project said teeth into the walls of said recess and lock said leg members in this position when said terminal is driven into said recess against the lower wall of said recess.

6. An electrical terminal suitable for mounting in a support by driving a portion of the terminal into a recess formed in the support, said terminal comprising a lower portion having an elongated aperture formed therein, a pair of leg members extending in spaced relation and defining said aperture, a foot on each leg member sloping downwardly and inwardly toward a corresponding foot on the other leg member, said feet being readily bendable at the junctures of said feet with said leg members and being arranged to engage each other in a toe-to-toe manner and outwardly thrust said leg members into holding engagement with the walls of said recess and locksaid leg members against withdrawal from said recess when said terminal is driven into said recess and against the lower wall of said recess.

7. An electrical terminal suitable for mounting in a support by driving a portion of the terminal into a recess formed in the support, said terminal comprising a lower portion having an elongated aperture formed therein, a pair of leg members extending in spaced relation and defining said aperture, a foot on each leg member sloping downwardly and inwardly toward a corresponding foot on the other leg member, teeth formed on the outer edge of each leg member, said teeth being directed toward the upper end of said terminal, said feet being readily bendable at the junctures of said feet with said leg members and being arranged to engage each other in a toeto-toe manner and to outwardly thrust said leg members to project said teeth into the walls of said recess and lock said leg members in this position when said terminal is driven into said recess and against the lower wall of said recess.

DOUGLAS H.

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